Digital computers are used to perform a wide variety of tasks in business, industry, government, education, entertainment, and the home. Modern computers often incorporate powerful integrated circuits to implement complex functions such as 3-D graphics, voice recognition, and the like.
Because of the wide range of computer uses and applications, together with the cost constraints imposed by different users, computer manufacturers have had to produce computers with different capabilities to satisfy different market segments. This has often required different configurations of computer microprocessors, dedicated digital processors, memory, motherboards, input/output functions, display devices and power supplies. For example, while desktop computers can benefit by using higher power consumption to improve performance, in portable computers low power consumption may be more important than high performance. One method of reducing power consumption is to reduce the power supply voltage. In particular, the power consumption of random access memory (RAM) can be significantly reduced by using a lower power supply voltage.
Because of competitive pressure, even as computer systems become more powerful their manufacturers are pressured to control costs. One method of controlling costs is to reduce the number of different types of devices that must be purchased and inventoried. For example, a significant cost when manufacturing a computer system is the motherboard, which usually carries the system's power supply and RAM. Since some RAM will not operate properly on a reduced voltage, and since processors require specific operating voltages, a manufacturer has had to configure the power supply voltage to match the RAM and the processor, possibly requiring multiple voltage supplies. Having to configure the power supplies to match the RAM and the processor causes logistical problems for computer manufacturers.
While RAM typically has been located on a motherboard, a new semiconductor package, the Mobile Accelerated Graphics Port Package (MAP) from NVIDIA®, the assignee of the present invention, packages both RAM and a Graphics Processor Unit (GPU) together. Because of the different cost, speed, and performance options available with RAMs and GPUs, such packaging enables different processor-RAM combinations to be offered to higher-level system manufacturers. This enables those manufacturers to offer systems with different cost, speed, and performance options while using the same motherboard, but without the logistical problems of configuring that motherboard for different RAM types. Additionally, MAP-packaged processor-RAM combinations benefit the MAP manufacturer by allowing for competitive pricing and backup suppliers.
While packaging processors and RAM together is highly beneficial, manufacturers nonetheless still had to match their power supplies to the processor and RAM. Tracking the various configurations remained difficult. For example, a low power MAP-packaged processor-RAM combination might be able to operate on low voltage (say 2.7V); while another MAP-packaged processor-RAM combination might be operable at both 3.3 and 5 volts. Furthermore, to optimize performance, another MAP-packaged processor-RAM combination might operate with the RAM at 3.3V while the GPU might operate best at 5V. Complicating the problem is that the MAP-packaged processor-RAM combination supplier might want to be free to use various GPU-RAM combinations based on cost or supply considerations without notifying the computer manufacturer what power supplies are required.
Therefore, a method of controlling a power supply or power supplies using a device package having both memory and a processor would be beneficial.